JPEG hw decoder

JPEG hw decoder

[rd bairva]

Hi ,
      My board has a hardware JPEG decoder. I want to write a driver
for this in Linux kernel, But it seems there that no Framework exists
in kernel. Can somebody provide me some pointers?

Thanks in advance.


Regards,
Rbairva

JPEG hw decoder

[rd bairva]

Hi ,
      My board has a hardware JPEG decoder. I want to write a driver
for this in Linux kernel, But it seems there that no Framework exists
in kernel. Can somebody provide me some pointers?

Thanks in advance.


Regards,
Rbairva

JPEG hw decoder

[Baurzhan Ismagulov]

On Wed, Jul 28, 2010 at 10:42:53AM +0530, rd bairva wrote:
>       My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

http://lwn.net/Kernel/LDD3/

You'd probably want to define the application interface using open /
read / write / ioctl / poll / close and implement them in a character
device.

With kind regards,
Baurzhan.

Re: JPEG hw decoder

[Baurzhan Ismagulov]

On Wed, Jul 28, 2010 at 10:42:53AM +0530, rd bairva wrote:
>       My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

http://lwn.net/Kernel/LDD3/

You'd probably want to define the application interface using open /
read / write / ioctl / poll / close and implement them in a character
device.

With kind regards,
Baurzhan.

JPEG hw decoder

[viresh kumar]

On 7/28/2010 10:42 AM, rd bairva wrote:
> Hi ,
>       My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

Hello Rbairva,

Which JPEG decoder are you working on??

I have Synopsys JPEG Decoder/Encoder on ST SPEAr platform
and i am currently working on its driver for LKML.

I already have a driver for it which is not aligned to LKML guidelines,
and so doing modifications there.
In my driver i have used char device framework and none other suits it well.

viresh.

Re: JPEG hw decoder

[viresh kumar]

On 7/28/2010 10:42 AM, rd bairva wrote:
> Hi ,
>       My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

Hello Rbairva,

Which JPEG decoder are you working on??

I have Synopsys JPEG Decoder/Encoder on ST SPEAr platform
and i am currently working on its driver for LKML.

I already have a driver for it which is not aligned to LKML guidelines,
and so doing modifications there.
In my driver i have used char device framework and none other suits it well.

viresh.

JPEG hw decoder

[Eric Miao]

On Wed, Jul 28, 2010 at 4:15 PM, viresh kumar <viresh.kumar@st.com> wrote:
> On 7/28/2010 10:42 AM, rd bairva wrote:
>> Hi ,
>> ? ? ? My board has a hardware JPEG decoder. I want to write a driver
>> for this in Linux kernel, But it seems there that no Framework exists
>> in kernel. Can somebody provide me some pointers?
>
> Hello Rbairva,
>
> Which JPEG decoder are you working on??
>
> I have Synopsys JPEG Decoder/Encoder on ST SPEAr platform
> and i am currently working on its driver for LKML.
>
> I already have a driver for it which is not aligned to LKML guidelines,
> and so doing modifications there.
> In my driver i have used char device framework and none other suits it well.
>

Normally the JPEG decoder/encoder comes with the video camera
module, which falls in v4l2 framework. Though not sure how well
the v4l2 API is gonna support this.

> viresh.
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

Re: JPEG hw decoder

[Eric Miao]

On Wed, Jul 28, 2010 at 4:15 PM, viresh kumar <viresh.kumar@st.com> wrote:
> On 7/28/2010 10:42 AM, rd bairva wrote:
>> Hi ,
>>       My board has a hardware JPEG decoder. I want to write a driver
>> for this in Linux kernel, But it seems there that no Framework exists
>> in kernel. Can somebody provide me some pointers?
>
> Hello Rbairva,
>
> Which JPEG decoder are you working on??
>
> I have Synopsys JPEG Decoder/Encoder on ST SPEAr platform
> and i am currently working on its driver for LKML.
>
> I already have a driver for it which is not aligned to LKML guidelines,
> and so doing modifications there.
> In my driver i have used char device framework and none other suits it well.
>

Normally the JPEG decoder/encoder comes with the video camera
module, which falls in v4l2 framework. Though not sure how well
the v4l2 API is gonna support this.

> viresh.
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

JPEG hw decoder

[Pawel Moll]

Hi,

>       My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

If I was to do the same, I'd look around V4L2 API. If covers things like
video encoders/decoders etc. The only problem is that the particular
area you are interested in is not well defined yet:

http://linuxtv.org/downloads/v4l-dvb-apis/ch04s05.html

This means that people usually extend the API in their own way, staying
within the framework itself, obviously.

Maybe you could ask about this on the linux-media mailing list?

http://vger.kernel.org/vger-lists.html#linux-media

Good luck!

Pawe?

Re: JPEG hw decoder

[Pawel Moll]

Hi,

>       My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

If I was to do the same, I'd look around V4L2 API. If covers things like
video encoders/decoders etc. The only problem is that the particular
area you are interested in is not well defined yet:

http://linuxtv.org/downloads/v4l-dvb-apis/ch04s05.html

This means that people usually extend the API in their own way, staying
within the framework itself, obviously.

Maybe you could ask about this on the linux-media mailing list?

http://vger.kernel.org/vger-lists.html#linux-media

Good luck!

Paweł

JPEG hw decoder

[rd bairva]

Hi ,
     My board has a hardware JPEG decoder. I want to write a driver
for this in Linux kernel, But it seems there that no Framework exists
in kernel. Can somebody provide me some pointers?

Can V4l2 be used?
Thanks in advance.


Regards,
Rbairva

RE: JPEG hw decoder

[Pawel Osciak]

Hi,

> rd bairva wrote:
>     My board has a hardware JPEG decoder. I want to write a driver
>for this in Linux kernel, But it seems there that no Framework exists
>in kernel. Can somebody provide me some pointers?
>
>Can V4l2 be used?
>Thanks in advance.

please take a look at the mem2mem (memory-to-memory) framework, it has
been designed just for such hardware, i.e. hardware that takes a source
buffer, processes the data and returns the result in another buffer.

You can find a short introduction in an LWN article at:
http://lwn.net/Articles/389081/

More info in the original threads:
http://www.spinics.net/lists/linux-media/msg14063.html
http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/10668


Best regards
--
Pawel Osciak
Linux Platform Group
Samsung Poland R&D Center

JPEG hw decoder

[Guennadi Liakhovetski]

On Wed, 28 Jul 2010, rd bairva wrote:

> Hi ,
>       My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

drivers/media/video, maybe v4l2-mem2mem kind of thing.

Regards
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: JPEG hw decoder

[Guennadi Liakhovetski]

On Wed, 28 Jul 2010, rd bairva wrote:

> Hi ,
>       My board has a hardware JPEG decoder. I want to write a driver
> for this in Linux kernel, But it seems there that no Framework exists
> in kernel. Can somebody provide me some pointers?

drivers/media/video, maybe v4l2-mem2mem kind of thing.

Regards
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Fwd: JPEG hw decoder

[rd bairva]

Hi,
  If I write the jpeg driver using v4l2-mem2mem.
  Than i think i need to write custom applications for the kernel
  driver. Are there some application available to use this v4l2-mem2mem?

Reagrds
Ramdayal

---------- Forwarded message ----------
From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Date: Thu, Jul 29, 2010 at 11:38 AM
Subject: Re: JPEG hw decoder
To: rd bairva <rbairva@gmail.com>


On Thu, 29 Jul 2010, rd bairva wrote:

> Hi Guennadi,
>                       If I write the jpeg driver using v4l2-mem2mem.
> Than i think i need to write custom applications for the kernel
> driver. Are there some application available to use this v4l2-mem2mem?

Please ask on

Linux Media Mailing List <linux-media@vger.kernel.org>

Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

RE: JPEG hw decoder

[Pawel Osciak]

>rd bairva wrote:
>  If I write the jpeg driver using v4l2-mem2mem.
>  Than i think i need to write custom applications for the kernel
>  driver. Are there some application available to use this v4l2-mem2mem?

There is no other interface for jpeg codec hardware in V4L2 as far
as I am aware anyway. That's why mem2mem has been developed in the first
place. Mem2mem has just been released (in 2.6.35), so you have to give
it some time. That said, I don't think you will find any other (non-mem2mem)
V4L2-based applications for jpeg hardware either. Somebody might prove
me wrong on this though...

Best regards
--
Pawel Osciak
Linux Platform Group
Samsung Poland R&D Center